中文摘要：

混凝土收缩徐变效应使大跨度钢筋混凝土拱桥的变形随时间不断发展,采用劲性骨架法施工的高速铁路混凝土桥梁由收缩徐变引起的时变行为更复杂,因此,合理预测桥梁结构施工阶段和成桥后的时变变形对高速铁路的安全运营十分重要。本文对主跨445m的高速铁路劲性骨架混凝土拱桥进行1∶7.5的大比例缩尺模型试验,采用GL2000混凝土收缩徐变模型预测拱桥模型的时变变形,考虑混凝土收缩徐变的随机性影响,得到原桥长期变形的概率结果。研究结果表明：拱桥模型的试验结果能够较好反映原桥的时变变形;对于大跨度混凝土桥梁的收缩徐变,确定性分析得到的长期预测结果偏不安全;原桥建成10年后,跨中截面位移增量均值为8.1cm,针对结构的残余收缩徐变变形,建议桥面铺设可调标高量较大的有砟轨道。

英文摘要：

The deformation of long-span reinforced concrete arch bridge will be increased with time because of creep and shrinkage effect.Particularly in the case of the concrete bridge constructed with stiffening frame technique,the time-variant effects caused by shrinkage and creep may be extremely complicated.Therefore,reasonable prediction of the time-variant deformation of the bridge during the construction and service stage is crucial for the safety operation of the high-speed railway.In this paper,a 1∶7.5scaled model test based on the445 m main span concrete arch bridge reinforced with rigid skeleton on the high-speed railway was carried out.The GL2000 concrete creep and shrinkage model was used to predict the time-variant deformation of the arch bridge model,to obtain the probability results of long-time deformation of the actual bridge,with consideration of stochastic effects of the creep and shrinkage of the concrete.The results showed that the predicted results of the arch bridge model can well reflect the time-variant deformation of the actual bridge.For long-span concrete bridges,the results obtained by the deterministic analysis of the creep and shrinkage for the prediction of longterm deformation were unsafe.The average value of displacement increment of the cross section of the span center was 8.1cm ten years after the actual bridge was built.In view of the residual deformation caused by shrinkage and creep,ballasted track with large adjustable range of elevation is recommended to be laid on the bridge deck.